The Raiders said Asomugha, 32, will announce his retirement officially at a news conference at team headquarters Friday.

Asomugha had his greatest success in the NFL with the Raiders, totaling 11 interceptions after being drafted in the first round out of California in 2003. He earned three Pro Bowl selections in eight seasons in Oakland and was a first-team All-Pro in 2008 and '10.

Asomugha struggled after joining Philadelphia as a high-profile free agent in 2011, a contract that paid him $25 million guaranteed. After two seasons with the Eagles, Asomugha played three games with San Francisco this season, making only two tackles, before being cut last month.

Oakland said Asomugha will be joined at his announcement Friday by legendary Raiders defensive backs Willie Brown, Lester Hayes and Charles Woodson.